Images such as photography, paintings, and moving pictures may include objects affected by one or more light sources. The light sources may affect the visual imagery of objects in an image, yet are absent in the image itself. For example, a light bulb located beside a photographer may affect the visual imagery of the objects in an image obtained by the photographer. In computer vision and graphics, estimation of an image lighting environment is helpful for many applications. The location and relative intensity of one or more light sources may be helpful in recreating the lighting environment to obtain a second image or to ensure a consistent lighting environment when re-shooting a motion picture scene, for example.
Conventional methods for obtaining lighting environment information from images capture information concerning characteristics associated with a single light source and involve invasive techniques. Thus, they have limited ability to capture lighting environment characteristics and may disrupt the image.